On August 15, 1995, a Bell 206B, N193JB, registered to Huebner Aviation Inc., operating as a 14 CFR Part 91 personal flight, made a power-on authoritative precautionary landing to an open area after hearing a "pop" while in cruise flight. The helicopter sustained substantial damage. Visual meteorological conditions prevailed and no flight plan was filed. The commercial pilot and one passenger reported no injuries. The flight originated from Opa Locka, Florida, about 45 minutes before the accident. The pilot stated he was in cruise flight at 500 feet agl, when he observed the engine oil temperature gauge just short of the red line. A short time later, he heard a noise described as a "pop". He entered a power-on autorotation straight ahead to an open area, and planned to terminate the autorotation to a hover. The engine out warning light was not illuminated, the engine out audio did not activate, and the remaining engine instruments appeared to be normal. At 50 to 60 feet he initiated a deceleration and applied initial collective pitch at about 15 feet while increasing power and leveling the helicopter. He noticed the landing area was unsuitable, and observed the N2 decreasing. He applied aft cyclic, the helicopter collided with the ground ventral fin first, rocked forward and the main rotor blades collided with the tailboom before the helicopter came to a complete stop. Examination of the engine compartment by recovery personnel at the crash site revealed a shop rag was observed wrapped around the tail rotor driveshaft section on the inside of the oil cooler. There was no damage to the oil cooler, tailrotor driveshaft section and the hanger bearing. Examination of the helicopter was conducted by Allison Engine Company in the presence of the FAA. There was no evidence of a precrash mechanical failure of the airframe or flight control assembly. A 1 foot x 1.5 foot section of plexiglas from the upper left hand portion of the left wind screen was broken out. The windscreen retaining flange along the left-hand side evidenced areas of bending/flexing where the plexiglas had worked back and forth against the metal. No evidence of a bird strike was observed. A rigging check was conducted, and N1 and N2 continuity was established. No deficiencies were noted. The engine was removed and transported to an authorized repair facility. The engine was placed in an engine test cell. The engine was started, run at idle power, and accelerated to takeoff power level. (For additional information see Allison Accident Investigation Report). The helicopter wreckage was released to Mr. Steve Smalley, President, Air Sea and Recovery on August 21, 1995. The engine assembly and accessories was released to Mr. Smalley on August 23, 1995. The helicopter logbooks and pilot logbook were released to Comet Courier Service as directed by Mandina, Ginsberg and Toledo, P.A., Miami, Florida, on August 25, 1995.